My Sarracenia lagoons are basically large water trays, each 6ft x 2ft x 3" (1800 x 600 x 75 mm) ( that is internal depth). I made them up from wood and covered inside with pool liner. The Disa are in live sphagnum + perlite and sit in the lagoon from spring to late autumn in about 2" (50mm) of rainwater. I use no fertiliser as they and some other orchids, share the lagoon/s with carnivorous plants. To keep them frost free in winter I transfer the Disa to a well ventilated cellar and keep them under LED growlight arrays that I also designed and made, as the lighting is much much cheaper to run than keeping a greenhouse frost free. They seem to enjoy that treatment. It's all very easy and simple( I like things that way).
If you're interested I could also post on my new little Darlingtonia house.